There is known in general in the prior art a number of methods for protecting the contents of a flexible container through the use of a reusable closure. One of the most widely used methods for resealing or reclosing flexible containers involves the use of a separate component such as a twist tie or plastic clip. These methods, however, have several disadvantages due to the fact that the reusable seals are not part of the container. The plastic clips or twist ties may often be misplaced between uses and also require some degree of fine motor control, therefore making their use difficult for the young, the elderly and the physically handicapped to use. Additionally after repeated use, plastic clips often break and the twist ties expose their sharp metal wire support making their use hazardous. These closures may also pose a risk of choking or other hazards for small children who may have access to them. These types of closures can also cause tears in the flexible containers.
Another known construction utilizes Ziploc.RTM. and similar zipper-like sealing means to provide the containers with a reusable air tight seal. This construction adds substantially to the cost of the container and adds difficulty to its manufacture. Furthermore, these systems also require some fine motor control which may prove difficult for some user populations.
Previous attempts at developing reusable sealing means involving pressure sensitive adhesive were largely unsuccessful or unnecessarily complex. Many resealable systems were unreliable in that after a limited number of reclosures the seal would often fail to further adhere. Other systems require components which had to be manufactured using methods of die cutting or other off line processes thereby prohibitively raising the cost of such systems.
One example of a reclosing system is shown in U.S. Pat. No 4,552,269, which discloses a resealable device consisting of a paper or foil blank and a sealing flap. While this is an improvement over prior resealable devices, this device still requires production through die cutting means and provides only a limited size opening which can be resealed. Another system is shown in U.S. Pat. No. 4,584,201 which shows use of an adhesive strip positioned parallel to a top sealed edge of a container. The top edge can be folded upon itself and then adhered to the strip for a particular specific type of container.